Understanding Nutrient & Sediment Loss at Breneman Farms - 7 Dry Matter Intake and Manure Production for Management Intensively Grazed Dairy Cattle Kevan Klingberg and Dennis Frame – UW Extension/Discovery FarmsDennis Cosgrove – UW-River Falls
Breneman Farms On-farm research was conducted on the Breneman farm to investigate environmental challenges and opportunities for grass-based dairies on the Wisconsin landscape, 2002-2007. While cooperating with the UW-Discovery Farms Program, pasture and dairy herd management information from this farm was compiled within a larger pool of statewide farm information through a USDA Sustainable Agriculture Research and Education (SARE) project. The Breneman farm was one of seven farms utilized for on-farm research associated with a SARE project titled: “Nutrient Management Planning for Dairy Farms Practicing Management Intensive Rotational Grazing.”
Breneman Farms Grazing-based dairy. 42 paddocks. 80 crossbred dairy cows + young stock. (1.6 acres / AU) Coarse textured soil Out-winter cows and older heifers Columbia County, WI
Grazing-based Dairy Grass-based dairies have existed in Wisconsin since we began milking cows. While many dairies have moved cattle into confinement facilities, the Wisconsin dairy industry includes an important and ever-growing group of producers who practice Management Intensive Grazing (MIG). In the past several years the interest in MIG has been increasing, as demonstrated in the 2004 Agricultural Statistics, which indicates that about 14 percent of the state’s dairy operations were utilizing some version of managed grazing.
Grazing-based Dairy Grazing systems allow producers to begin or continue dairying with minimal investment in equipment on farms where their daily activities center on managing grass and dairy animals. As with any farming system, there are many variations within rotational grazing, which include choices in the frequency of moving cattle, the types of facilities to house and milk cattle, and the method to produce milk - either conventionally or organically. The use of MIG farming systems can be done with dairy cattle, beef, sheep or any other form of livestock capable of utilizing forage-based systems.
Grazing-based Dairy Grass-based dairy systems simultaneously combine grazing animals, actively growing pasture forage, paddock fences, watering facilities, travel lanes, and generally some type of low-cost housing facilities. These systems greatly minimize the need for mechanical forage harvesting equipment, feed storage and handling and intensive housing facilities, as well as manure storage, handling and hauling.
Grazing-based Dairy Dairies practicing MIG report increased profitability as a result of lower feed, energy, equipment, and labor costs, as well as improved animal health and lower veterinary costs. Although Wisconsin studies have shown that when managed correctly, both grazing and non-grazing dairy systems can be profitable, a University of Wisconsin - Center for Dairy Profitability study shows that the nine year average (1999-2007) total basic costs on grazing dairies were $650 less per cow, compared to confinement dairies. Similarly, grazing dairies earned $230 more net farm income per cow compared to confinement operations over the same time period.
Grazing-based Dairy At the heart of this farming system is a focus on ruminant livestock harvesting high quality forage via grazing and spreading their own manure in the process.
Grazing-based Dairy Pastures are (usually) delineated by permanent perimeter fences further subdivided by temporary fencing connected by travel lanes watering systems in common areas Cattle are systematically moved into and out of paddocks eating good quality fresh pasture forage followed by a rest period that allows adequate time for the perennial grass and legume plants to re-grow before the next grazing cycle.
Grazing-based Dairy UW - Extension publication A3529, “Pastures for profit: a guide to rotational grazing” covers the basics of setting up rotational grazing (MIG) on your farm.
Feed and Manure on Grazing Dairies Nitrogen, phosphorus and other nutrients applied in an agricultural system continuously cycle from the soil to crops to feed to livestock to manure, and back to the soil. Dairies practicing MIG uniquely fit into this cycle as cattle are deliberately moved through a series of paddocks, eating forage plants and naturally depositing manure to the paddocks along the way.
Feed and Manure on Grazing Dairies Grazing cattle spread their own manure, bypassing the need for on-farm manure storage and mechanical manure applications. Similarly, grazing cattle harvest their own forages, bypassing the need for mechanical harvesting and on-farm feed storage.
Feed and Manure on Grazing Dairies Dairy herd managers must know how much feed their cattle are consuming to properly balance rations. Dry matter intake (DMI) is a standard term used for the moisture-free amount of feed an animal eats. DMI is relatively easy to determine for animals that are offered a known quantity of feed at the barn or from a feed bunk. Within confinement operations, the total pounds of feed offered minus pounds of feed uneaten at the end of the day equals daily DMI.
Feed and Manure on Grazing Dairies Determining DMI for rotationally grazed dairy cattle becomes more challenging because pasture condition and forage quality vary seasonally. Also, the actual amount of forage eaten is a function of pre-grazing pasture condition and plant material present minus post-grazing plant material remaining.
Feed and Manure on Grazing Dairies Dairy cattle eating mixed feed delivered in the barn. Dairy cow grazing on grass + legume pasture.
Feed and Manure on Grazing Dairies The nutrient content of manure and the amount of manure generated by individual dairy cows is a function of their size, diet, feed utilization efficiency, and milk production. Similar to determining DMI for confinement dairy systems, determining manure generated within confinement dairies is relatively easy. Confined livestock manure production can, for the most part, be measured since almost all manure is captured in gutters, feedlots, or manure storage facilities.
Feed and Manure on Grazing Dairies Again, determining manure generated by a grazing animal is more challenging because the material is deposited naturally within paddocks as cows eat pasture forage.
Feed and Manure on Grazing Dairies Liquid manure from a confinement barn; stored, pumped, transported and applied to cropland. Dairy cows on MIG pasture, eating forage and naturally depositing manure.
Feed and Manure on Grazing Dairies It is important for dairy producers who practice MIG to be able to determine how much pasture forage the cows are eating each day so that a large enough paddock is offered to the cows. It is also important to have a good handle on the forage quality so that a ration can be balanced by supplementing the correct amount of additional forages, concentrates, minerals and other dietary materials, as needed. Also, within grazing dairies, knowledge of manure volume generated is a critical value necessary to make sure enough pasture land is utilized for natural manure deposition and to accurately credit manure nutrients toward pasture crop nutrient needs.
SARE Study Design A three year on-farm research study was conducted to improve nutrient management planning and implementation on dairy farms that practice MIG, 2003-2005. Pasture growth and quality were measured and farm information was collected from 7 WI dairy farms. Evaluated the accuracy of four methods that MIG dairy producers use to determine DMI of cows on pasture. Refined current estimates for daily manure production from grazing dairy cattle.
SARE Study Design Collect and analyze pasture forage samples for quality before and after each grazing cycle. Measure milk production during the time when cows were in each sampled paddock. Collect and analyze manure 5 times / farm to define average nutrient content. Gather information about amount and quality of supplemental feed in ration.
SARE Study Design Determine pasture dry matter availability before and after each grazing cycle using four different methods: Clipping: Clip, dry and weigh plant material from representative areas within paddocks. Plate: Use pasture plate to partially compress fresh standing plant material from a small known area. Measure plant height. Multiply plant height x farm-specific calibration of pounds of dry matter per inch of plant height. See: http://www.uwex.edu/ces/forage/wfc/COSGROVE.html Height: Measure plant height directly and multiply by a defined constant for pounds of dry matter per inch of (uncompressed) plant height.
Energy: Utilize a simple energy balance equation. Identify daily quantities and net energy of lactation for stored and supplemental feed eaten daily per cow. Factor cow body weight, milk production and milk composition. Utilize energy balance equation, solving for remaining DMI necessary to produce measured daily milk.
SARE Study Design Estimate daily cow manure production using feed amounts and quality, along with milk production amounts and quality. Information on total feed intake levels of P and N and total P and N excreted in milk was used to estimate manure production required to excrete the remaining ingested P and N.
Results: Estimating DMI Dry matter intake was estimated each day for lactating dairy cows being fed in a MIG forage system. Four methods were used and compared to determine the accuracy and variability in estimating DMI. clipping and weighing; pasture plate; pasture height; energy balance Each of the methods could realistically be done on a commercial dairy grazing farm.
Results: Estimating DMI Estimate of pasture forage dry matter intake by four different methods ******************************************************** Method 2003 2004 2005 ……………………DMI (lbs / cow / day)………………………..
Results: Estimating DMI Of the four ways used to estimate DMI, the least reliable was measuring plant height and multiplying by a constant for lbs dry matter / inch of growth. This method generated the highest forage production estimate each year, and the greatest level of variation. Based on stocking rates and measured milk production, this study determined that the height method overestimates forage production, thus overestimating DMI.
Results: Estimating DMI Two of the other methods, clipping and the pasture plate, both generated similar DMI estimates when compared to each other annually. The annual difference in DMI prediction between clipping and plate to be approximately one pound. Yet, both clipping and plate DMI estimation methods had a high enough level of variation (+/- 3 to 8 lbs per day) that accurate ration balancing was not possible.
Results: Estimating DMI The energy balance method had the most consistent DMI estimates with minimal variability. Even though the energy method requires more information to use, it also provides the most accurate estimate of a grazing cow’s actual DMI. A spread sheet was developed to estimate pasture DMI using the energy balance method: Pasture Forage Intake Calculator for Dairy Cows, http://www.uwrf.edu/grazing/DMI.xls.
Results: Estimating Manure Production The solid feces portion of manure generated by grazing dairy cattle was estimated to be 85 pounds per cow per day. Mathematically determined using the seven MIG dairy herds and three years of feed ration nutrient analysis, and milk production nutrient analysis. N and P budgets were developed such that total N and P feed intake levels and total N and P output in milk was used to estimate manure production required to excrete the remaining N and P.
Results: Estimating Manure Production When urine was accounted for, the total manure production increased to 120 pounds per day. similar to the value currently used in Wisconsin for 1,200-pound dairy cows for nutrient management planning USDA-NRCS Nutrient Management Standard - 590 and WI Conservation Planning Technical Note, 2005
Outreach Information generated from this project has been incorporated into UW - Extension Grazing Schools that train producers and agriculture professionals in Wisconsin: http://www.uwex.edu/ces/regionalwaterquality/conservationtraining/grazing.cfm
A fact sheet and associated spreadsheet has been developed by Dr. Dennis Cosgrove and Dr. Dennis Cooper, UW-Extension Specialists, UW-River Fall: 1) Estimating Dry Matter Intake of Grazing Dairy Cattle: http://www.uwex.edu/ces/crops/uwforage/GN-EstimatingDMintake.pdf; Pasture Forage Intake Calculator for Dairy Cows: http://www.uwrf.edu/grazing/DMI.xls.
Wisconsin nutrient management planning software SNAP Plus has been updated to reflect the information generated from this study. SNAP Plus can be downloaded at http://www.snapplus.net/.
Conclusions Nitrogen and phosphorus cycle on livestock farms from soil to crops to feed to livestock to manure, and back to the soil. Grazing cattle spread their own manure, minimizing the need for on-farm manure storage and mechanical manure applications. Grazing cattle also harvest most of their own forages, reducing the need for mechanical harvesting and on-farm feed storage and handling.
Conclusions This project found that an energy balance method was the most accurate and reliable way for dairy producers who practice MIG to determine how much pasture forage the cows are eating each day (DMI). This project also confirmed that the estimated amount of daily manure produced by a 1,200-pound lactating dairy cow (120 pounds per day) is in line with current nutrient management planning guides.
Conclusions For more information about SARE Project LNC03-237 contact: Dr. Dennis Cosgrove, UW – River Falls, Department of Plant and Earth Science, 410 S 3rd St, River Falls, WI 54022. 715-425-3745. Dennis.email@example.com. Project details can also be found at www.sare.org by searching for project number LNC03-237.
Information Available This presentation is the seventh in a series of seven developed to provide the data and information collected at Breneman Farms. All of the presentations, factsheets and briefs are available on the UW - Discovery Farms website. http://www.uwdiscoveryfarms.org